Power systems such as large internal combustion engines, for example, burn hydrocarbon-based fuels or similar fuel sources to convert the chemical energy therein to mechanical energy for powering an associated machine or application. Combustion of the hydrocarbon fuel may release or create several byproducts or emissions, such as nitrogen oxides (NOX), carbon monoxides and carbon dioxides (CO and CO2), and particulate matter. The quantity of some of these emissions that may be released to the environment may be subject to government regulations and environmental laws. Accordingly, manufacturers of such power systems may equip the system with an associated exhaust gas aftertreatment system to treat the emissions before they are discharged to the environment.
The exhaust gas aftertreatment system can be disposed in the exhaust channel of the power system and may include one or more of a diesel oxidation catalyst (DOC) unit, a DPF unit, and an NOX reducing device through which the exhaust gasses may pass. The module may include one or more DPF canisters that can filter out most or all of the particulate matter in a diesel engine exhaust stream. The DPF canisters contain an appropriate filtering material, such as wall flow filter arrangements, ceramic fiber filters, metal fiber filters, paper, partial filters and the like. The diesel exhaust stream enters through an inlet side of the aftertreatment module and the DPF canisters. Particulate matter in the diesel exhaust stream is caught by the filtering material, and filtered exhaust gas exits through an outlet side of the module and DPF canisters. The filtered exhaust gas is discharged to the atmosphere or passes through additional NOx treatment components before being discharged.
Over time, the particulate material builds up and increases the pressure required to force the exhaust gas through the filtering material in the DPF canisters. The buildup can ultimately cause engine performance issues. In some implementations, the accumulated particulate material, or soot, may be combusted and converted to ash by a regeneration process while the DPF canisters remain installed. However, the ash buildup will still ultimately lead to excess material buildup and performance degradation. Consequently, the befouled DPF canisters must be replaced with fresh DPF canisters.
An issue arises where the DPF canisters as constructed can be turned around in the aftertreatment module instead of properly replaced and serviced. Money can be saved through such reuse, but blowing the accumulated soot and ash out through the aftertreatment system can potentially damage or render ineffective downstream components, or discharge the material into the atmosphere in violation of emission standards. Aftertreatment systems have been developed to prevent reversal of DPF canisters. For example, U.S. Pat. Appl. Publ. No. 2014/0041369 A1, published on Feb. 13, 2014, for Golin et al. and entitled, “Poka-Yoke Mounting System for an Exhaust Treatment Device,” disclosed an exhaust treatment system including an exhaust treatment device having a stepped outer diameter. First and second clamps each include a stepped inner diameter such that the clamps engage the exhaust treatment device and other portions of the exhaust treatment system when the exhaust treatment device is properly oriented. The exhaust treatment device interferes with one of the clamps to preclude coupling the exhaust treatment device to an adjacent portion of the exhaust treatment system when an attempt is made to install the exhaust treatment device in a reversed improper orientation. A consistent exhaust flow direction through an exhaust treatment device such as a diesel particulate filter may be maintained through use of the system. The poka-yoke mounting system requires the modification and/or addition of multiple parts of the DPF canister retention components. In view of this, opportunities exist for improving DPF canisters and installation systems that ensure proper orientation and installation of the DPF canisters.